Radar Observed MJO Convection during Dynamo: Properties, Evolution, and Spatial Variability

Friday, 19 December 2014
Weixin Xu and Steven A Rutledge, Colorado State University, Fort Collins, CO, United States
One of the overarching objectives of the DYNAMO radar-sounding array is to understand and document the structure and evolution of cloud and precipitation processes. The ship-based (R/V Revelle and R/V Mirai) observations were parallel to those on the Gan Island, located ~800 km to the west. Analysis of the Gan Is. supersite data along with the observations from the R/V Revelle and R/V Mirai allow us to address the spatial variability of convection and environmental conditions associated with MJO initiation. The radar network also helps document the broader MJO convective envelope as it propagates slowly eastward, exiting the initiation region. Preliminary results show that the evolution of rainfall, precipitation types, and convective depth throughout the MJO life cycle are very similar between Gan Is. and R/V Revelle over the equator. On the other hand, precipitation and convection exhibit little MJO signature over R/V Mirai ~800 km off the equator. Precipitation tends to be more convective over the R/V Mirai than over the equator during DYNAMO. This study fully examines the convective properties and cloud population throughout the MJO life cycle using radar observations from these three locations.